Ibuprofen is now a well-known, useful, anti-inflammatory compound which can be named chemically as 2-(4-isobutylphenyl)propionic acid. To our knowledge, ibuprofen is presently crystallized, in commercial scale processes, from commercial hexane or heptane. These aliphatic hydrocarbon solvents characteristically produce ibuprofen crystals which are rod or needle shaped. Historically, compounds which exist in the rod or needle crystal shape or habit have experienced poor flow and ibuprofen isn't any exception to this observation. Shape also seems to play a role in ibuprofen's tendency to stick to the faces of the tablet punches and dies during compressing and its tendency to laminate during decompression. In order to alleviate these undesirable manufacturing properties, the physical pharmacists must develop a formulation which will mask all of these traits. Seldom is a formulation successful in obtaining all of these goals. Therefore, pharmaceutical production and process research personnel have continued to search for chemical and physical process procedures which will improve upon the manufacturing of the currently available ibuprofen.
It was known generally about compound crystallization procedures that larger particles (40.mu..sup.+) had higher bulk densities. Also, it was known generally that larger particles (laths) were obtained as concentration of ibuprofen in the hexane or heptane solvent mixture magma was increased. Smaller particles (&gt;20 .mu.) are obtained at lower concentrations (0.35 to 0.2 g/cm) and they are acicular/laths. However, to our knowledge, no one knew that large particle crystalline ibuprofen having higher bulk density, lower bulk volume, excellent flow properties, and different particle shape (equant and hexagonal) could be obtained by crystallization of ibuprofen, an acid, from any solvent which has a hydrogen bonding solubility parameter Index (.delta.H) of at least 8 Hilderbrand units.